<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <title>IFE ECMAScript</title>
    <style>
        select {
            display: none;
        }
    </style>
</head>

<body>
    <label>
        <input id="school" name="status" type="radio">
        School
    </label>
    <label>
        <input id="company" name="status" type="radio">
        Company
    </label>

    <select id="school-select">
        <option>北京邮电大学</option>
        <option>黑龙江大学</option>
        <option>华中科技大学</option>
    </select>

    <select id="company-select">
        <option>百度</option>
        <option>爱奇艺</option>
    </select>
</body>
<script>
    var school = document.getElementById("school");
    var company = document.getElementById("company");
    var schoolSelect = document.getElementById("school-select");
    var companySelect = document.getElementById("company-select");
    console.log(schoolSelect);
    console.log(companySelect);

    function changeStatus(e) {
        if (e.target.id === "school"  /* &&  e.target.checked */ ) {
            var schoolSelect = document.getElementById("school-select");
            var companySelect = document.getElementById("company-select");
            schoolSelect.style.display = "block";
            companySelect.style.display = "none";
        } else if (e.target.id === "company"  /* &&  e.target.checked */) {
            var schoolSelect = document.getElementById("school-select");
            var companySelect = document.getElementById("company-select");
            schoolSelect.style.display = "none";
            companySelect.style.display = "block";
        }
    }
    school.addEventListener("click", changeStatus);
    company.addEventListener("click", changeStatus);
</script>

</html>